He said: "Although understandably the agencies want to restrict the information and not cause panic, I think what they've done in some cases is actually cause panic by withholding too much information."

Prof Harsh Duggal, director of the West Midlands North Health Protection Unit, said: "We have worked very closely with our partner organisations to make sure the necessary control measures were taken quickly to find a potential source.

"Working in this way has enabled us to get the results we have and minimised the impact on the wider public."

Dr Zafar Iqbal, the director of public health for NHS in Stoke-on-Trent, said: "It's important to remember that Legionnaires' disease cannot be passed from person to person.

"The early symptoms of legionella infection include a 'flu-like' illness with muscle aches, tiredness, headaches, dry cough and fever."

He added that anyone with concerns should contact NHS Direct on 0845 46 47 or see their GP.